handle multiple PR links back-to-back
handle multiple PR links back-to-back

Signed-off-by: Conor Evans <ee51414e84df50401e75572969514b5578ff4654@tcd.ie>

GoogleCloudPlatform/prometheus,prometheus/prometheus,alileza/prometheus,alileza/prometheus,alileza/prometheus,prometheus/prometheus,keegancsmith/prometheus,prometheus/prometheus,keegancsmith/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,keegancsmith/prometheus,keegancsmith/prometheus